Abstract:

A treatment method is provided that is entirely different from
conventional treatment methods in that it is capable of sufficiently
suppressing pain and the recurrence of all the bacterial intraoral
diseases without depending on removal of living tissues. This treatment
method is a lesion-sterilizing and tissue-repairing treatment method
including the processes of: washing teeth affected with bacterial
intraoral disease with a washing treatment solution; administering a
treatment composition to the washed teeth; and covering an opening of the
teeth. This treatment composition includes an antibacterial agent having
an antibacterial property against intraoral bacteria and a base
containing polyethylene glycol 400, polyethylene glycol 600, polyethylene
glycol 6000, and propylene glycol.

2. A treatment method according to claim 1, wherein the base contains
polyethylene glycol 400 of not less than 13 percent volume and not more
than 19 percent volume; polyethylene glycol 600 by not less than 13
percent volume and not more than 19 percent volume; polyethylene glycol
6000 by not less than 27 percent volume and not more than 38 percent
volume; and propylene glycol not less than 36 percent volume and not more
than 50 percent volume.

3. A treatment method according to claim 1, wherein the washing treatment
solution contains EDTA at a pH of about 7 and a water-soluble thickener
containing no metallic ions.

4. A treatment method according to claim 3, wherein the washing treatment
solution contains EDTA of not less than 10 percent volume and not more
than 12 percent volume of this washing treatment solution.

5. A treatment method according to claim 1, further comprising a
hemostatic process of stopping bleeding from pulp and/or gingival prior
to the covering process, wherein the hemostatic process is a process of
stopping the bleeding from pulp and/or gingival using a hemostatic
treatment solution containing sodium alginate and zinc oxide.

6. A treatment method according to claim 5, wherein the hemostatic
treatment solution contains sodium alginate of not less than 6.0 percent
volume and not more than 6.5 percent volume of this hemostatic treatment
solution, and zinc oxide of not less than 33 percent volume and not more
than 35 percent volume.

8. A treatment composition according to claim 7, wherein the base contains
polyethylene glycol 400 of not less than 13 percent volume and not more
than 19 percent volume of this base; polyethylene glycol 600 of not less
than 13 percent volume and not more than 19 percent volume; polyethylene
glycol 6000 of not less than 27 percent volume and not more than 38
percent volume; and propylene glycol of not less than 36 percent volume
and not more than 50 percent volume.

9. A washing treatment solution to be used for washing teeth comprising
EDTA at a pH of about 7 and a water-soluble thickener containing no
metallic ions.

10. A washing treatment solution according to claim 9 containing EDTA of
not less than 10 percent volume and not more than 12 percent volume.

12. A hemostatic treatment solution according to claim 11 comprising
sodium alginate of not less than 6.0 percent volume and not more than 6.5
percent volume as well as zinc oxide of not less than 33 percent volume
and not more than 35 percent volume.

13. A treatment kit for bacterial intraoral diseases comprising:basic
ingredients of a treatment composition for bacterial intraoral disease
comprising an antibacterial agent having an antibacterial property
against intraoral bacteria and a base containing polyethylene glycol 400,
polyethylene glycol 600, polyethylene glycol 6000, and propylene glycol;a
washing treatment solution to be used for washing teeth comprising EDTA
at a pH of about 7 and a water-soluble thickener containing no metallic
ions; anda hemostatic treatment solution used for stopping bleeding from
pulp and/or gingival comprising sodium alginate and zinc oxide.

14. A treatment method according to claim 2, further comprising a
hemostatic process of stopping bleeding from pulp and/or gingival prior
to the covering process, wherein the hemostatic process is a process of
stopping the bleeding from pulp and/or gingival using a hemostatic
treatment solution containing sodium alginate and zinc oxide.

15. A treatment method according to claim 3, further comprising a
hemostatic process of stopping bleeding from pulp and/or gingival prior
to the covering process, wherein the hemostatic process is a process of
stopping the bleeding from pulp and/or gingival using a hemostatic
treatment solution containing sodium alginate and zinc oxide.

16. A treatment method according to claim 4, further comprising a
hemostatic process of stopping bleeding from pulp and/or gingival prior
to the covering process, wherein the hemostatic process is a process of
stopping the bleeding from pulp and/or gingival using a hemostatic
treatment solution containing sodium alginate and zinc oxide.

[0002]Conventionally, as a typical example of a treatment method for
bacterial intraoral diseases (such as caries, pulp disease, apical
periodontal disease and periodentitis), a treatment method provided with
the following constitution has been cited.

[0003]FIG. 8 depicts a cross-sectional view of a tooth 100 affected with
caries, an example of a bacterial intraoral diseases, and pulp disease.

[0004]The tooth 100 is of a structure comprising, from the outside, in
order, enamel 130, dentin 140, and dental pulp 150, and embedded into the
alveolar bone 180 via cement 160 and a periodontal membrane 170. This
alveolar bone is covered with gingival 190.

[0005]The invasion of the intraoral bacteria 111 into the inside of the
tooth 100 results in the formation of a dental caries site 110. This
dental caries site 110 comprises free enamel, a smear layer, tissue in
which bacteria exist, etc.

[0006]FIG. 9 is a cross-sectional view showing the state of the tooth 100'
when the tooth 100 of FIG. 8 has been treated with a treatment method
according to the conventional example.

[0007]The above-described conventional treatment method comprises the
processes of: grinding off the caries site 110 from the tooth 100
affected with the bacterial intraoral disease to remove the dental pulp
150, and covering the opening 120' of the tooth 100' with a filling
material (not shown) from which the caries site 100 has been ground off
and the dental pulp 150' has been removed (see, e.g., Patent Document 1).

[0008]With this treatment method, since the opening 120' of the tooth 100'
is covered after the dental caries site 110 is ground off and the dental
pulp 150 is removed, the bacterial intraoral disease can be treated as
far as the intraoral bacteria 111 are completely eliminated.

[0010]However, with the above-described treatment method, when the
invasion of intraoral bacteria 111 has reached the dental pulp 150, in
order to eliminate the intraoral bacteria 111 and avoid causing toothache
after the treatment, there is no other way but to remove the dental pulp
150 of the crown, generally the dental pulp 150 not only of the crown but
also from the crown to the root of tooth (see FIG. 9).

[0011]Also due to the extreme difficulty in accurately identifying the
range of the caries site 110, the complete elimination thereof is often
hindered in the grinding process. When the caries site 110 cannot be
completely eliminated, problems are posed such as the recurrence of
bacterial intraoral disease due to the repropagation of the remaining
intraoral bacteria inside the tooth 100' after the aforementioned
covering process.

[0012]Accordingly, in order to improve the possibility of complete
elimination of the caries site 110, measures have been taken to grind off
not only the site identified as the caries site 110 but also the
surrounding sites thereof.

[0013]However, with the progress of the disease, when the intraoral
bacteria 111 spread to the depth of the dentin 140, the cement 160, and
the periodontal membrane 170, the complete elimination of the intraoral
bacteria 111 becomes more difficult.

[0014]Accordingly, in such a case, there is no other way but to abandon
the treatment by grinding and deal with the intraoral disease by the
extraction of the tooth 100 as a whole.

[0015]Thus the conventional treatment method depended on the exhaustive
elimination of living tissue to prevent the recurrence of bacterial
intraoral disease.

[0016]The present invention has been made in view of the above-described
problems, and one object thereof is to provide a treatment method
independent of the elimination of living tissue and capable of
sufficiently suppressing pain caused to the subject and the recurrence of
bacterial intraoral diseases, a treatment composition, a washing
treatment solution, and a hemostatic treatment solution.

[0017]The inventors of the present invention have adopted a treatment
method of internal medicine, which is entirely different from the
conventional treatment method depending on the physical elimination of
living tissue, to the dental treatment, thereby achieving the present
invention.

[0019](1) A treatment method for the bacterial intraoral diseases
comprising the processes of: washing a tooth affected by bacterial
intraoral disease with a washing treatment solution, administering a
treatment composition to the washed tooth, and covering the tooth
opening, in which the treatment composition comprises:

[0020]an antibacterial agent having an antibacterial property against
intraoral bacteria and

[0023](2) The treatment method according to (1) in which the
above-described base contains polyethylene glycol 400 of not less than 13
percent volume and not more than 19 percent volume of this base,
polyethylene glycol 600 of not less than 13 percent volume and not more
than 19 percent volume, polyethylene glycol 6000 by not less than 27
percent volume and not more than 38 percent volume, and propylene glycol
by not less than 36 percent volume and not more than 50 percent volume.

[0024](3) The treatment method according to (1) or (2) in which the
above-described washing treatment solution contains EDTA at a pH of about
7 and a water-soluble thickener containing no metallic ions.

[0025](4) The treatment method according to (3) in which the
above-described washing treatment solution contains EDTA of not less than
10 percent volume and not more than 12 percent volume of this washing
treatment solution.

[0026](5) The treatment method according to any one of (1) to (4) which
further comprises, prior to the above-described covering process, a
hemostatic process of stopping the bleeding from the dental pulp and/or
gingival in which the above-described hemostatic process is a process of
stopping bleeding from the dental pulp and/or gingival using a hemostatic
treatment solution containing sodium alginate and zinc oxide.

[0027](6) The treatment method according to (5) in which the
above-described hemostatic treatment solution contains sodium alginate of
not less than 6.0 percent volume and not more than 6.5 percent
volume--and zinc oxide of not less than 33 percent volume and not more
than 35 percent volume of this hemostatic treatment solution.

[0028](7) A treatment composition for bacterial intraoral disease which
has an antibacterial agent having an antibacterial property against
intraoral bacteria and a base containing polyethylene glycol 400,
polyethylene glycol 600, polyethylene glycol 6000, and propylene glycol.

[0029](8) The treatment composition according to (7) in which the
above-described base contains polyethylene glycol 400 of not less than 13
percent volume and not more than 19 percent volume of this base,
polyethylene glycol 600 of not less than 13 percent volume and not more
than 19 percent volume, polyethylene glycol 6000 of not less than 27
percent volume and not more than 38 percent volume, and propylene glycol
of not less than 36 percent volume and not more than 50 percent volume.

[0030](9) A washing treatment solution to be used for washing teeth which
contains EDTA at a pH of about 7 and a water-soluble thickener containing
no metallic ions.

[0031](10) The washing treatment solution according to (9) which contains
EDTA of not less than 10 percent volume and not more than 12 percent
volume.

[0032](11) A hemostatic treatment solution to be used to stop bleeding
from dental pulp and/or gingival which contains sodium alginate and zinc
oxide.

[0033](12) The hemostatic treatment solution according to (11) which
contains sodium alginate of not less than 6.0 percent volume and not more
than 6.5 percent volume and zinc oxide of not less than 33 percent volume
and not more than 35 percent volume.

[0034](13) A treatment kit for bacterial intraoral diseases which
comprises basal ingredients for the treatment composition according to
(7) or (8), the washing treatment solution according to (9) or (10), and
the hemostatic treatment solution according to (11) or (12).

[0035]"Basal ingredients" refer to the respective compounds constituting
the treatment composition in the state prior to being mixed together.
More specifically, the respective compounds are antibacterial agents
including metronidazole, minocycline, and ciprofloxacin as well as a base
including polyethylene glycol 400, polyethylene glycol 600, polyethylene
glycol 6000, and propylene glycol.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036]FIG. 1 depicts a cross-sectional view of a tooth affected with
bacterial intraoral disease at an early stage of treatment by a treatment
method according to a first embodiment of the present invention.

[0037]FIG. 2 depicts a cross-sectional view of the tooth of FIG. 1 at a
subsequent stage, at which the tooth has been treated by the treatment
method according to the above-described embodiment.

[0038]FIG. 3 depicts a cross-sectional view of the tooth of FIG. 1 at a
further subsequent stage, at which the tooth has been treated by the
treatment method according to the above-described embodiment.

[0039]FIG. 4 depicts a cross-sectional view of a tooth affected with
bacterial intraoral disease at an early stage of treatment by the
treatment method according to a second embodiment of the present
invention.

[0040]FIG. 5 depicts a cross-sectional view of the tooth of FIG. 4 at a
subsequent stage, at which the tooth has been treated by the treatment
method according to the above-described embodiment.

[0041]FIG. 6 depicts a cross-sectional view of the tooth of FIG. 4 at a
further subsequent stage, at which the tooth has been treated by the
treatment method according to the above-described embodiment.

[0042]FIG. 7 depicts a cross-sectional view of a sample in a test example
of the present invention.

[0044]FIG. 9 depicts a cross-sectional view of the tooth of FIG. 8 which
has been treated by a treatment method according to a conventional
example.

DESCRIPTION OF SYMBOLS AND NUMERALS

[0045]1 tooth,

[0046]13 treatment drug layer

[0047]14 latching site

[0048]16 intraoral bacteria

[0049]21 filling material layer

[0050]22 glass-ionomer cement layer

[0051]23 dental luting agent layer

[0052]24 sterilized tissue

PREFERRED MODE FOR CARRYING OUT THE INVENTION

[0053]In the following, preferred embodiments of the present invention are
described with reference to the drawings. Herein, in descriptions of
respective embodiments other than the first embodiment, items common to
those in the first embodiment are marked with the same symbol (numeral),
and descriptions thereof are omitted or simplified.

First Embodiment

Treatment Composition

[0054]Treatment composition of the present invention has an antibacterial
agent and a base.

Antibacterial Agent

[0055]Antibacterial agent has an antibacterial property against intraoral
bacteria. This antibacterial agent is a combination of desired
antibiotics for killing all of a wide variety of intraoral bacteria,
including, for example, metronidazole, minocycline, and ciprofloxacin. A
combination of these three types of ingredients is considered to exert
the antibacterial action against all of the intraoral bacteria.

[0056]Considering antibacterial effects against intraoral bacteria,
content ratios of the respective ingredients are preferably set such that
potency ratios of metronidazole:minocycline:ciprofloxacin are
1˜3:1:1.

[0062]Polyethylene glycol is mixed with the powdered antibacterial agents
to change them into a pasty or ointment-like preparation, thereby
improving the operability thereof and facilitating the measurement of
doses of the treatment composition.

[0064]Polyethylene glycol 400 improves penetrability of the treatment
composition. Polyethylene glycol 600 has a melting point of about 18
degrees Celsius such that it is solid extraorally for easy loading
thereof onto administering tools, while it is liquidized intraorally and
improved in its soaking properties for its administering easily to teeth.
In addition, polyethylene glycol 6000 increases viscosity of the
treatment composition thereby improving the operability.

[0065]Besides these, a mixture of polyethylene glycol 4000 and
polyethylene glycol 400 can be also used.

[0066]In addition, there are no particular limitations to polyethylene
glycol, and, for example, "Solbase (brand name)" (Dainippon
Pharmaceutical Co.) may be used.

[0067]Propylene glycol adjusts the viscosity of anti-bacterial agents
which have been changed into pasty or ointment-like preparations.
Adjustment of the treatment composition to the desired viscosity results
in improving the penetrability thereof. Propylene glycol also has
sterilizing effects against intraoral fungi.

[0068]Considering the effects of various ingredients as described above,
the base preferably contains polyethylene glycol 400 at not less than 13
percent volume and not more than 19 percent volume, polyethylene glycol
600 at not less than 13 percent volume and not more than 19 percent
volume, polyethylene glycol 6000 at not less than 27 percent volume and
not more than 38 volume percent, and propylene glycol at not less than 36
percent volume and not more than 50 percent volume.

Preparation Method

[0069]First, the desired amounts of antibacterial agents are separately
placed into mortars and pulverized with a pestle to prepare the
anti-bacterial agents for mixing.

[0070]Furthermore, after a desired amount of propylene glycol is poured
into a beaker-shaped vessel, polyethylene glycol is added in small
portions to this propylene glycol until the desired viscosity is reached,
and gently mixed to obtain the base.

[0071]These antibacterial agents and the base are mixed in the desired
ratios to prepare the treatment composition.

[0072]Considering that there is a possibility that when the base content
is too high, the treatment composition is so soft that the operability
thereof conversely deteriorates and at the same time may become unable to
thoroughly sterilize bacteria due to insufficient antibacterial agents,
antibacterial agents may be mixed so as to contained not less than 5
percent volume and not more than 7 percent volume (volume ratio) with
respect to the base in general.

[0073]In this case, the treatment composition readily deteriorates to lose
treatment effects thereof. Thus, it is preferably prepared just prior to
its use. In other words, basal ingredients of the treatment composition,
antibacterial agents in particular, are preferably stored separately in a
dark cold place. Furthermore, when the treatment composition is stored
after its preparation, in order to prevent its deterioration, it is
preferably stored in a sealed vessel under shaded conditions with low
temperature and low humidity. However, even under such conditions, period
during which the treatment composition is effective is usually about two
days.

Washing Treatment Solution

[0074]The washing treatment solution of the present invention is used for
washing teeth, specifically containing EDTA at a pH of about 7 and a
water-soluble thickener without metallic ions.

[0075]EDTA acts as a chelating agent for the free calcium of teeth.
Accordingly, the washing treatment solution containing EDTA chelates and
eliminates the free calcium so as to remove microorganisms embedded in
the free calcium. Furthermore, since the washing treatment solution, if
acidic, decalcifies teeth, and, if alkaline, inhibits the calcium
precipitation, the pH of the washing treatment solution is preferably
near 7.

[0076]In addition, when the EDTA content is too low, the efficiency of
capturing the free calcium becomes insufficient, while, when too high,
the efficiency of capturing the free calcium is saturated so as to be
disadvantageous from the point of view of cost. Therefore, the EDTA
content is preferably not less than 10 percent volume and not more than
12 percent volume.

[0077]Thickeners confer viscosity on the washing treatment solution to
retard the outflow thereof from teeth and secure the time required for
performing elimination of microorganisms and such by EDTA. Furthermore,
since thickeners preferably contain no metallic ions in order that
thickeners are stable with respect to EDTA. An example of such thickeners
is dextrin.

[0078]When the dextrin content is too small, the washing treatment
solution rapidly flows out from the teeth due to the insufficient
viscosity thereof, while when too large, the penetration of the EDTA into
the teeth is inhibited. The dextrin content is preferably not less than
2.7 percent volume and not more than 3.0 percent volume.

[0079]Although solvents for the washing treatment solution are not
particularly limited, one example thereof is purified water.

Preparation Method

[0080]Dotite 2NA and Dotite 4NA are added in this order to the purified
water in equal amounts (by volume ratio) to dissolve them. After the
dissolution, the amount of the purified water is adjusted such that the
EDTA concentration becomes 24 percent volume.

[0081]To the EDTA concentration-adjusted solution is added an equal amount
(by volume ratio) of dextrin, and the solution is mixed to prepare the
washing treatment solution. As a result, the washing treatment solution
contains EDTA at a concentration of 12 percent volume.

Hemostatic Treatment Solution

[0082]The hemostatic treatment solution of the present invention is used
to stop bleeding from dental pulp and gingival when they bleed in a
removal process, washing process, etc., described below. Specifically,
the hemostatic treatment solution contains sodium alginate and zinc
oxide.

[0083]Sodium alginate covers the bleeding site to suppress historrhexis
from mucosa.

[0084]Zinc oxide binds with proteins existing in teeth and gingival to
form a film so as to exert vasoconstrictive, antiphlogistic, protective,
and antiseptic actions. Zinc oxide also absorbs exudate and suppresses
the secretion thereof to dry the wounded surface.

[0085]When the sodium alginate content is too low, it cannot sufficiently
suppress the historrhexis from mucosa, while when too high, the
hemostatic treatment solution does not diffuse well over the entire
bleeding site due to the excessive increase in its viscosity. The sodium
alginate content is preferably not less than 6.0 percent volume and not
more than 6.5 percent volume.

[0086]When the zinc oxide content is too low, it cannot sufficiently stop
the bleeding from a wounded surface, while when too high, the
above-described action is saturated so as to be disadvantageous in the
aspect of cost. The zinc oxide content is preferably not less than 33
percent volume and not more than 35 percent volume.

[0087]There are no particular limitations to solvents for the hemostatic
treatment solution, and, for example, the purified water may be cited.

Preparation Method

[0088]Sodium alginate is added to the purified water at a 10:1 volume
ratio for dissolution. To the solution thus obtained, zinc oxide is added
at a 100:55 volume ratio for dissolution to prepare the hemostatic
treatment solution.

[0089]In the following, one embodiment of the treatment method of the
present invention is explained with reference to the figures.

Treatment Method

[0090]A treatment method in the present invention includes the processes
of: washing teeth affected with bacterial intraoral disease using the
washing treatment solution; administering the treatment composition to
the washed teeth, and covering the teeth opening.

[0091]The treatment method may further include, prior to the washing
process, the processes of: forming a latching site to which the covering
material is latched in the covering process, and forming an
administrating site on which a sufficient amount of the treatment
composition is loaded. The treatment method may further include, prior to
the covering process, a hemostatic process to stop the bleeding from the
dental pulp.

Latching Site Formation Process

[0092]The latching site formation process is a process of mechanically
removing the free calcium (e.g. free enamel and smear layer) from a tooth
affected with bacterial intraoral disease to form a latching site to
which covering materials are latched (the latching sites 14 in the FIGS.
1 to 3 described below). The latching site formation may be performed
using the known means (such as an excavator and turbine bar).

[0093]From the aspect of suppressing pain to the subject, it is preferable
to avoid grinding not only living tissues but also necrotic tissues
(softened dentin in particular) as much as possible. In this case,
although nerves in necrotic tissue are dead so that the removal thereof
primarily causes no pain to a subject, the operation often stimulates
nerves near the necrotic tissue to cause pain to the subject.

Administering Site Formation Process

[0094]The administering site formation process is a process of forming a
sufficiently wide administering site in the following administering
process when a sufficient space for loading the treatment composition is
not present in the subject's tooth, or a process to promote the treatment
composition delivery to the bacterial invasion site of alveolar bone and
the like, in the case of treatment of an infected root canal. That is,
this administering site formation process is an optional process to be
arbitrarily performed, taking the bacterial invasion range and such into
consideration.

[0095]In the case of an intraoral bacteria infection which has reached the
root canal and dental pulp, even when it is difficult to widen and build
the root canal and even when the root of the tooth is curved, a mere
loading of the treatment composition on the opening of the root canal
enables the passage of this treatment composition through the dentinal
canals and gaps between the root canal and root-filling material as well
as the diffusion and penetration thereof into the root canal and dental
pulp.

Hemostatic Process

[0096]The hemostatic process is a process of stopping the bleeding from
dental pulp and gingival prior to the washing process described below.
Hemostasis may be performed using the above-described hemostatic
treatment solution, and, more specifically, after covering the bleeding
site with this hemostatic treatment solution usually for about 1 to 2
minutes, it is removed by gently applying a water gun to the treated
site.

[0097]Since the remaining hemostatic treatment solution interferes with
treatment effects of the treatment composition administered in the
administration process described below, it is preferable to remove the
hemostatic treatment solution as much as possible.

Washing Process

[0098]The washing process is a process of washing teeth after the latching
site formation process and before the administering process described
below. Washing of the remaining free calcium in the washing process
further promotes the following diffusion and penetration of the treatment
composition into bacteria-infected tissues.

[0099]Washing may be performed using the above-described washing treatment
solution, specifically by spouting the washing treatment solution from
the tip of a washing tool provided with a fine tube nozzle.

Administration Process

[0100]The administration process is a process of administering the
above-described treatment composition to a tooth from which the free
calcium has been removed. More specifically, a nearly spherical treatment
composition of about 1 mm in diameter is loaded on a suitable position of
tissue in which bacteria exist. Thereby the loaded treatment composition
diffuses and penetrates into tissue with bacteria so as to sterilize the
bacteria-invaded site.

[0101]FIG. 1 depicts a cross-sectional view of the tooth 1 in an early
stage of treatment by the treatment method according to a first
embodiment of the present invention.

[0102]In the tooth 1, the caries site 12 is formed in the dentin due to
the invasion of intraoral bacteria, which have reached the dental pulp as
shown by dots in FIG. 1. In this tooth 1, the treatment composition is
layered on the administering site built up on the caries site 12 to form
the treatment drug layer 13.

[0103]Other structures of the tooth l are common to those of the
above-described tooth 100 and explanations thereof are omitted.

Covering Process

[0104]The covering process is a process of covering the opening of a tooth
administered with the treatment composition. By covering the opening, the
invasion of intraoral bacteria into the sterilized site is blocked so as
to maintain sterile conditions. Specifically, the tooth opening is
covered with a filling material (e.g. glass-ionomer cement "Fuji IX GP
(brand name)" (G C Co., Ltd.)) so as to cover the administered treatment
composition.

[0105]In addition, in the case of root canal treatment, after the
above-described treatment composition is applied to its administering
seat, it may be covered with hydraulic cement (e.g. "Caviton (registered
trade mark)" (G C Co., Ltd.)) which may be further covered with phosphate
cement.

[0106]FIG. 2 depicts a cross-sectional view of the tooth 1' in the next
stage of treating the tooth 1 of FIG. 1 by the treatment method according
to the first embodiment of the present invention.

[0107]In the tooth 1', filling materials are layered over the
above-described opening 20 to build up the filling material layer 21,
which is latched to the tooth 1' by the latching sites 14. Other
structures of the tooth 1' are common to those of the above-described
tooth 100 and the explanations thereof are omitted.

[0108]When left standing under these conditions, the treatment composition
diffuses from the treatment drug layer 13 to the caries site 12 and
sterilizes the caries site 12 with this diffusion to form sterilized
tissue 24.

[0109]FIG. 3 depicts a cross-sectional view of the tooth 1'' in a further
stage of treating the tooth 1 of FIG. 1 by the treatment method according
to the first embodiment of the present invention.

[0110]In the tooth 1'', the glass-ionomer cement ("Fuji IX GP (brand
name)") and the luting agent in which crown-repairing element is bound
with adhesive resinous cement are layered in this order over the opening
20 which has been exposed by removing the above-described filling
material layer 21, thereby forming the glass-ionomer cement layer 22 and
the luting agent layer 23. Furthermore, the treatment composition
diffuses into the dental pulp so as to eliminate the intraoral bacteria
16.

[0111]Other structures of the tooth 1'' are common to those of the
above-described tooth 100 and explanations thereof are omitted.

[0112]With the treatment method according to the above-described
embodiment, formation of the treatment drug layer 13 over the caries site
12 alone enables the diffusion of the treatment composition over the
entire tooth 1 and sterilization of intraoral bacteria. Accordingly, even
though intraoral bacteria have reached the depth of dentin, bacterial
intraoral diseases can be treated without removing living tissue.

Second Embodiment

[0113]This embodiment differs from the first embodiment in the treatment
method constitution.

[0114]FIG. 4 depicts a cross-sectional view of the tooth 1A in an early
stage of treatment by the treatment method according to the second
embodiment of the present invention.

[0115]In the tooth 1A, the intraoral bacteria 16A necrotize the dental
pulp further invading the alveolar bone from the inside of the tooth.
When the tooth is left untreated under such conditions, periodontitis is
induced.

[0116]A treatment method in the present invention for such symptoms
(infected root canal treatment) is further provided with a root canal
filling process in which necrotic pulps within the root canal are removed
and this root canal is filled with the filling material mediating
diffusion of the treatment composition.

Administration Site Formation Process

[0117]FIG. 5 depicts a cross-sectional view of the tooth 1A' in the next
stage of treating the tooth 1A of FIG. 4 with the treatment method
according to the second embodiment of the present invention.

[0118]An administering site formation process of the treatment method
according to the second embodiment of the present invention is a process
of grinding the dentin to form the administering site 15 having a
diameter larger than that of the root canal at the opening of the root
canal. Depth of the administering site 15 is usually set to be not less
than 2 mm.

[0119]In this way, the efficiency of delivering the treatment composition
to the bacterial invasion sites such as the alveolar bone can be
promoted.

Root Canal Filling Process

[0120]The root canal filling process is, when the infected root canal
treatment is performed, a process of: eliminating the necrotic dental
pulp inside the root canal prior to the washing process described below
and filling this root canal with the root canal filling material 26
mediating diffusion of the treatment composition into this root canal.

[0121]In this case, a complete removal of the necrotic pulp is not
necessarily required, and the necrotic pulp 12A' may remain in a deep
portion of the root canal.

[0122]As a root-filling material, gutta-percha and apatite-type sealers
can be used.

[0123]FIG. 6 depicts a cross-sectional view of the tooth 1A'' in a further
stage of treating the tooth with the treatment method according to the
second embodiment of the present invention.

[0124]The treatment composition diffuses from the treatment drug layer 13A
through the root filling material 26 to the necrotic pulp 12A' and to the
alveolar bone such that the sterilized tissue 24A is formed and the
intraoral bacteria 16A are sterilized.

[0125]With the treatment method according to the above-described
embodiment, formation of the treatment drug layer 13A over the
administering site 15 alone enables the diffusion of the treatment
composition through dentinal canals and gaps between root canal and
root-filling material to the alveolar bone, and the lime, thereby
achieving the sterilization of bacterial invasion sites such as alveolar
bone, and the like.

[0126]In this case, since nerves in necrotic pulps are dead, the removal
thereof does not cause much pain to the subject.

[0127]With the treatment method according to the above-described
embodiment, even when the root of the tooth is curved, the treatment
composition passes through dentinal canals and gaps between root canal
and root-filling material, diffuses and penetrates into the alveolar
bone, and the like, thereby enabling the sterilization of bacterial
invasion sites such as alveolar bone, etc.

EXAMPLE

Test Example 1

Base

[0128]FIG. 7 depicts a cross-sectional view of a sample 50 according to
the present test example.

[0129]First, the mandibular first premolar affected with apical
periodontitis was drilled with a #70 reamer to enlarge the root canal and
further the root canal 51 was filled using a gutta-percha point and a
sealer, and by pressing them sideways. Subsequently a nearly cylindrical
hole about 2 mm deep from the cervical line and about 1.5 mm in diameter
was formed (hereinafter this hole is referred to as the drug application
seat 52 of the above-described administering site). At the bottom of this
drug application seat 52, two small pieces 53 (about 1.0 mm in diameter)
of each base shown in Table 1 added with food red were loaded.
Furthermore, cotton ball (not shown) was placed so as to cover these
small pieces 53, and "Caviton (registered trade mark)" (G C Co., Ltd.)
was layered over this cotton ball to form the covering layer 54, thereby
preparing the sample 50.

[0130]After the root portion of each sample 50 was embedded in an ordinary
gypsum block 55, it was stored under 100% humidity.

[0131]Migration distances of food red from the drug application seat for
storing times of 24 hours and 48 hours were measured to assess the
penetrability of the base contained in each sample. These results are
shown in Table 2. In this case, the migration distance was determined as
the longest distance in the direction of depth (in the direction of the
arrow D in FIG. 7) of the area reached by coloring due to food red when
the sample 50 was observed from outside.

[0132]As shown in Table 2, it was proved that penetrability of the base is
best in sample #4, that is, the base containing polyethylene glycol and
propylene glycol. Herein sample #4 contained polyethylene glycol 4000 and
propylene glycol in a 3:1 ratio by mass, in other words, in a 1:1 volume
ratio.

Test Example 2

Washing

[0133]In Test Example 1, prior to loading small pieces of the base (sample
2), the drug application seat was washed by each of the following washing
methods.

[0135]In the washing treatment section 2, a cotton ball soaked in a 12
percent volume EDTA aqueous solution was loaded onto the drug application
seat, left standing for 60 seconds, washed with water and air-blown.

[0136]As to each washing treatment section, using the base of sample #2 in
Test Example 1, penetrability of the base was assessed by a similar
method as in Test Example 1. These results are shown in Table 3.

[0137]As shown in Table 3, since in either washing treatment sections, the
migration distance of food red was increased compared to the case of Test
Example 1, it was proved that washing treatment performed for the drug
application seat. enables the improvement of penetrability of the base.
It was demonstrated that in the washing treatment section 2, that is,
when washing is performed using a solution containing 12 volume percent
EDTA in particular, penetrability of the base is most improved.

[0138]Herein, the present invention is not limited to the above-described
embodiments, and modifications and improvements within the scope of
achieving the purpose of the present invention are included in this
invention.

INDUSTRIAL APPLICABILITY

[0139]With the present invention, the following effects can be obtained.

[0140]With a treatment method that does not include a grinding of living
tissue, pain caused to the subject can be suppressed.

[0141]By administering a treatment composition containing antimicrobial
agents capable of killing all intraoral bacteria and fungi to teeth, this
treatment composition diffuses and penetrates in tissue that contains
microbes and sterilizes them. Accordingly, since the repropagation of
bacteria or fungi inside the teeth is prevented after the covering
process, the recurrence of bacterial intraoral disease can be assuredly
prevented. Furthermore, by the spontaneous generation of tissue repairing
reactions such as calcium re-precipitation (remineralization), formation
of repairing dentin, and cement propagation, the tissue thus sterilized
are repaired almost to the state prior to the microbial infection,
regardless of whether necrotic tissue or living tissue is involved.

[0142]Accordingly, it is possible to treat bacterial intraoral disease,
and furthermore, without depending on the removal of living tissue, to
sufficiently suppress pain caused to the subject and prevent the
recurrence of bacterial intraoral disease.